High Light Acclimation in the Secondary Plastids Containing Diatom Phaeodactylum tricornutum is Triggered by the Redox State of the Plastoquinone Pool - Université Pierre et Marie Curie Accéder directement au contenu
Article Dans Une Revue Plant Physiology Année : 2013

High Light Acclimation in the Secondary Plastids Containing Diatom Phaeodactylum tricornutum is Triggered by the Redox State of the Plastoquinone Pool

Résumé

In diatoms, the process of energy-dependent chlorophyll fluorescence quenching (qE) has an important role in photoprotection. Three components are essential for qE: (1) the light-dependent generation of a transthylakoidal proton gradient; (2) the deepoxidation of the xanthophyll diadinoxanthin (Dd) into diatoxanthin (Dt); and (3) specific nucleus-encoded antenna proteins, called Light Harvesting Complex Protein X (LHCX). We used the model diatom Phaeodactylum tricornutum to investigate the concerted light acclimation response of the qE key components LHCX, proton gradient, and xanthophyll cycle pigments (Dd+Dt) and to identify the intracellular light-responsive trigger. At high-light exposure, the up-regulation of three of the LHCX genes and the de novo synthesis of Dd+Dt led to a pronounced rise of qE. By inhibiting either the conversion of Dd to Dt or the translation of LHCX genes, qE amplification was abolished and the diatom cells suffered from stronger photoinhibition. Artificial modification of the redox state of the plastoquinone (PQ) pool via 3-(3,4-dichlorophenyl)-1,1-dimethylurea and 5-dibromo-6-isopropyl-3-methyl-1,4-benzoquinone resulted in a disturbance of Dd+Dt synthesis in an opposite way. Moreover, we could increase the transcription of two of the four LHCX genes under low-light conditions by reducing the PQ pool using 5-dibromo-6-isopropyl-3-methyl-1,4-benzoquinone. Altogether, our results underline the central role of the redox state of the PQ pool in the light acclimation of diatoms. Additionally, they emphasize strong evidence for the existence of a plastid-to-nucleus retrograde signaling mechanism in an organism with plastids that derived from secondary endosymbiosis.
Fichier principal
Vignette du fichier
Manuskript third revision.pdf (776.64 Ko) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-01097826 , version 1 (09-01-2015)

Identifiants

Citer

Bernard Lepetit, Sabine Sturm, Alessandra Rogato, Ansgar Gruber, Matthias Sachse, et al.. High Light Acclimation in the Secondary Plastids Containing Diatom Phaeodactylum tricornutum is Triggered by the Redox State of the Plastoquinone Pool. Plant Physiology, 2013, 161, pp.853-865. ⟨10.1104/pp.112.207811⟩. ⟨hal-01097826⟩
514 Consultations
181 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More